Validated regional scale groundwater model Noardburgum

SUBSOL partner Vitens is looking for options to increase drinking water production in the region, without causing salinization of the groundwater bodies and well fields. The former Noardburgum well field (now SUBSOL pilot site) had to be abandoned in 1993 because of salinization.

Model-based decisions

The SEAWAT model was used to evaluate different scenarios to increase drinking water production in the region with 2 million m3 per year. Focus of the evaluations was on (the effects on) the regional salinity distributions (i.e. prevention of salinization) and on the salinity concentrations in surrounding well fields. One of the concerns is that full-scale Freshkeeper application at Noardburgum may result in increased salinity at Ritskebos, via a by-pass in the underground.

The scenario runs indicated that a sustainable additional 2 million m³/y drinking water production is possible both via the Ritskebos well field (standard wells) as well as at the Noardburgum well field by applying the Freshkeeper concept full-scale. Following these results, Vitens is aiming to increase production in 2018 by a combination of both scenarios: 1 million m3/y at each of the two well fields. As such, it is foreseen that the Freshkeeper concept will be applied full-scale (multiple wells) at Noardburgum within the timeframe of the SUBSOL project!

SEAWAT simulation run of Noardburgum Freshkeeper producing 2 million m3/yr drinking water. Animation shows the regional changes in salinity over a 50 years period in the lower part (145 – 150 meter below sea level) of the production aquifer. (Red = saline groundwater; blue = fresh groundwater).

Location of the two well fields: Noardburgum (abandoned in 1993, now SUBSOL reference site) and well field Ritskebos (in production).

Chloride concentrations when applying the Freshkeeper concept in full-scale (2 million m3/yr) at Noardburgum. Top: concentrations in the intercepted (and injected) brackish groundwater. Bottom: concentrations in raw water at Ritskebos (green), Noardburgum (red) and total mix of both (blue). Results from regional scale SEAWAT model.